Your question is confusing and conflicting...
On one hand you're asking US (the readers) to post on "if you had $1000 to spend on a shack?" implying that you want us to tell you WHAT WE WOULD BUY with $1000 for a shack, and on the other hand you say "Before people tell me that only "I" can tell what is best for me. I am asking my fellow enthusiasts for a little guidance"
Do you mean "me" as in you, or "me" as in the person trying to tell you?
Ok that got a little confusing.. hehe
If you're looking for guideance on stuff to buy for home scanning, and it relating to what your interests are. I'd have to say get a Uniden BC-760 I've read that for AERO/MILAIR it's one of the best out there. check out
http://www.milaircomms.com he has a lot of info on his shack.
The antenna is going to be a very important part. IF I HAD 1000 DOLLARS to spend with no restrictions, I'd try to find a 50 foot tower from a hamfest or something at a good price, probably in the 300-500 range, then get a 4 ft. section of piping and mount it cross way at the top of the tower to add more antennas.
I'd buy a HUSTLER DISCONE and probably a VHF groundplane cut for the aero band and mount those on either side of the cross bar with Belden RG-214 coax, and on the center of the mast I'd probably put a VHF/UHF beam on a roter. Using the same cable.
And then feed those into a multiplexer in the shack, and from the multiplexer you could connect however many scanners you wanted to those three antennas. check out milaircomms's setup. its really neat.
If the tower thing is too much, you could look at getting 5 10" sections of mast and errect that on the side of the house. height is very important. If I had the money and no restrictions thats what I would focus on. The structure and the antennas.